Electrical switching device



Jue 9, 1925. l A1,541,470

' G. A. BETULANDER ELECTRICAL SWITCHING DEVICE l Filed Aug. 17, 1921 l? 1 T1 I 5L s ll lV l Y l Y l Mfg 3 H M f m mgm? f7 www r( im? 5.431@ 5.43 .3.4 3 I2 3.4 34 4 4 j. 4 MY 'w 0R g Y v I I /f i Jl a ALI L2 ffl/ 22; L2 .01.3 E 4v .'pPatented June 9, 1925.

UNITED STATES PATENT OFFICE. a

GOTTHILF .ANSGARIUS BETULANDER, OF `SODER'JIORNS VILLASTAD, SWEDEN, .AS-

SIGNOR TO THE RELAY AUTOMATIC TELEPHONE-COMPANY, LIMITED, OF LONDON,

ENGLAND.

ELECTRICAL SWITCHING DEVICE.

Y Application filed August 17, 1921.- Serial No. 493,131.

To all whom z't may concern:

Be it known that I-, GoT'rHrLr ANsGARrUs BETULANDER, a subject of the King of Sweden, and resident of Sodertorns Villastad, Sweden, have invented a new and useful Improvement in) Electrical Switching Devices, of which the following is a specifica'- tion. y

This invention relates to switching devices employed in connection with a system of l electrical lines of two orders for connecting any line of the first order of which the electrical condition becomes modified to an,idle line of the second order. According to this invention means are provided whereby whilst the connecting means is dealing with a modified line of the first order, other lines of that order whose condition has been modified subsequently to i l0 that line, are disabledfrom connection but so soon as the connecting means is capable w of dealing with these lines they are enabled for connection. The invention is especially applicable to telephone systems and for the l5 sake of clarity itl will therefore be described in connection with a plant in which the lines ot the first order are lines by which operators at an exchange can transmit ordersand which can be connected for thls purpose to a line or lines of the second order by known switching devices adapted to distribnte the calls in such a Way that when a plurality of calls comes in at the same time to the switching section only one calling line can be connected at one time. By this invention a shifting device is combined with the call distributor, which device divides the calls into groups, (of which one group comprises such calls as have been switched into readiness for connection as soon as a line'of the second order becomes disengaged, vwhilst another group comprising calls which have come in later than the calls of the first group consists of lines which have not as vet been prepared for connection. the arrangement being such that. no call in the second group can be switched into readiness for connection before all the` calls 'in' the first group have been dealt with. S0 soon as the calls lof the first group have been dealt with, however, all" the lines of the second group are at once switched intoy readiness for connection and subsequent calls are prevented from connection until all .this second group has been dealt with, and so on.

' The sequence in which the calls are dispatched withinf' each group isarbitrary, it is true, but as the group contains a lesser number of calls than the total number of calls occurring at the same time, the aforesaid disadvantage will be materially reduced.

Such grouping of the .calling lines is effectedin the simplest manner by causing the shifting device, which preferably consists ot a relay, to affect the circuits or contacts through which the lines are marked as calling so that new lines cannot be marked as" calling, and consequently cannot be connected, before the shifting device has been correspondingly actuated, the latterl being then in turn controlled partly by members marking the common lines as engaged, and partly by call relays or the like, in such a manner that the Ashifting device is not brought into operation until all the common lines have been engaged, and shifting does not take place until all the lines, which have already been marked as calling, have been connected.

The invention is illustrated in the accompanying drawing, in which Figs. 1, 2 and show three different switching arrangements according to the invention.

In the switching arrangement shown in Fig. l, AL1,AL2,AL3`, and AL4 denote four speaking lines, for instance for the vexchange of orders between telephone operators, which lines may be connected to a common line GL, through relays MR1, MR2, MRS and MR4 respectively. To each line AL are allotted a call relay ARI, ARQ, ARB, and AR/l and a key K1, K2, K3, and K4 respectively. The shifting device consists of a relay OR. In this case the relays MR also form the 'call controller, in that the circuitsof lthese relays extend over series connected contacts cl, k2, 7c3, 7a4 in all the relays MR so that only one line AL can be connected at a time.

KR is a contact relay co-operating with the call controller.

For example, if an operator at hne ALI,

desires connection with line GL," she delished is maintained as long as the key K1 is depressed. H during this time other operators try to obtain connection, for instance over lines AL2 and AL3, by depressing corresponding keys K2 and K3, lines `AL2 and AL3 cannot immediately be marked as calling, because the circuit AR2 and A R3 is open at OR. Only when the prevailing connection is open and GL becomes disengaged, can the waiting operators be marked as calling, in that the circuit of OR is then broken at K1, in consequence-f whereof OR releases its amature and closes circuit 41 for AR2 and These .latter then attract their armatures simultaneously and connect themselves into the fcircuit 2, OR

- again attracts its armature, and thus prevents subsequent calls from being marked as calling. At the Sametime AR2 and AR3 close circuit 3 for MR2 and MR3, but relay MR2 immediately after breaks the circuit of MR3, and consequently only MR2 retains its armature attracted, over circuit 4 containing KR which brought into y operation. Of the two lines .AL-2 and AL3 only the former has thus been connected tc GL. `When the operator, releases K2,'circuit 4 of MR2 and KR is broken, whereasthe energization of OR is maintained over K3. MR2 and KR release their armatures and then close circuit 3 of MR3 which attracts its armature and conn ects itself into circuit 4, whereby connection between AL3 and GL is established.

Now,'if another o rator should have depressed for instance ey K4 before line AL3 U ad obtained its connection, she could not interfere with the call reviously marked on hne AL3, because OR) is still in its operative potion. Thus a later call cannot be dispatched before all the lines alread marked as calling have been conne .i Only on GL becoming disengaged by release of K3, is line AL4 marked as calling, connection being then established as just de- When calls are' very frequent the calls (orlines-AL respectively) are in this wa divided by OR into two groups, of whic one com rises lines already marked as calling, and) the other lines which have not as yet been marked as calling. con- 'sequence of the cali controller selecting the isK now again' calls in the order in which the correspondmarked ascaliing does not ta e place in.

the ro r se uence but as by the said divisibnp'f thile calls, thenumber of lines which may be simultaneously marked as calling, is reduced the disadvantageous effect of the call controller on the sequence of dispatch is considerably" reduced.

Fig. 2 shows a suitable embodiment of the switching'arrangement when a plurality of common lines is used. The figure shows two such lines GLI and GL2. In this case the connectionsare established by means of a known switching device in which the groups of contacts KG through 'which lines AL are connected to lines GL .are arranged in rows at right angles to each other, the said rows corresponding to the various lines AL and GL, the selection and actuation of the group KG, correspondingxto the connection in question, bein then effected by means vof anumber of mar 'ng relays MR corresponding to the various lines AL, and by a'number of connecting relays GR corresponding to the various lines GL, the said connecting relays GR co-operating with one another in such a manner that thel connection is established by energizing the rela s which correspond to the lines AL and G inl questien. The marking relay MR then effects such a marking of the groups KG inthe corresponding vertical row that the relay GR, which .is adapted to actuate the groups situated vin -the corresponding horizontal row, only actuatcs thegroup situated at the point of intersection between the horizontal and vertical rows in question. Moreover, there is provided in this arrangement a testing device comprising PR, by means of which that line GL is selected which for the time being is disengaged, and cut ofi' relays UR are allotted to the different lines AL.

On ALI calling for instance circuits 1,2, 3 and 4 are first completed as in Fig.`1 except that circuit 2 extends over contacts KGI 'KG2 in relays GR when any one of the Llilies GL is disengaged. KRD then s witches in relays PR to the test wires of lines GL, said test wires, if the respective lines are disengaged, being connected to earth at contacts KGS KGA in 'relays GR. lf both lines GL are assumed to be disengaged, a circuit 5 is n ow closed through each of the relays PRI and lPE2 and an operating winding on each of the relays GR', but as PRI immediately breaks circuit 5 of GR2, only GRI is brought into operation. A holding circuit 6 is then closed through the holding winding of GRI and cut-off relay URI. Thus connection is established over a number of relaysA i Thus AL?, and AL4 are marked as calling.

' "Now if a call occurs on AL2 while a previous connection is still maintained, AL2 is connected in like manner to GL2; The short circuit of OR and circuit 2 over OR are then discontinued, the said relay thus only now being brought into operation and. prevent-ing subsequent calls from being marked as calling. In case of calls occurringin AL3 and AIA while both lines GL are still engaged, these calls have noeffect until a line GL becomes disengaged. If for instance GLl first becomes disengaged, OR is first shortcircuited over contact KGl. On OR releasing its armature, circuits 1 of ARS, and AR4 are closed, the said relays at the same time attracting their armatures and switching themselves into circuits 2.

At the same time circuit 3 and then circuit 4 of MR3 are closed, the connection of ALS to GLI taking place -in the manner previously described. The short circuit of OR is again'discontinued, and the relay attracts its armature, thereby preventing subsequent calls from being marked as calling until AIA shall have obtained connection. Only on the call on AIA having been dispatched and a line GL having again become disengaged, may new calls be marked and dispatched.

Fig. 3 shows a modification of the arrangement according to Fig. 2, the lines AL being divided into two sections ALl, AL2,

AL?,v and ALl, AL2', ALSin order to avoid too many series connected contacts k, in relays MR. These sections as regards the shifting ar to be regarded as a' single sec-A tion, in t t the marking of waiting li-nes as calling takes place simultaneously in both sections, but the connection of the lines marked as calling takes place by sections, preference being given to the one section.

In Fig. 3 relay OR is` thus common to all lines AL and ALl, and further the testing relays PR are common to both sections. On the other hand, there is a controlling relayKR or KRl respectively for each section, these-relays controlling the circuits of the circuits of which are under the control of connecting relays GR, so that the same effect is obtained as in Fig. 2. Likewise, contacts k1 are arranged in special relays HR which are connected in series with respect to the relays MR. Thus this arrangecontacts k1 than may be obtained with relays MR. Lines GL are shown as connected to plugs P1, P2 co-acting with a plug switch K6, so that the line is marked engaged when the' corresponding plugI is raised. Moreover, lines GL are marked engaged at the moment of connection through relays BR which breakcontacts K6.' iVith the abovementioned exceptions, the mode'of operation is the sameas in Fig. 2, as will be readily understood by a comparison of the figures. l A

The keys K may obviously be contacts of relays which become operated upon a line.

AL becoming calling.

I claiml. The combination with a system of electrical lines of two orders in which any line of the first order upon its electrical condition becoming modified is enabled for connection to an idle line' of the second order and means for effecting the connections, of means whereby whilst the` connecting means is dealing with a modified line subsequently modified lines are disabled from controlling the connecting means and whereby such subsequently modified lines are all enabled and maintained in condition for connection and .thereafter connected one at a time.

2. T he combination with a systemof electrical lines of two orders in which any line of the first order nponits electrical condition becoming modified is enabled for connection to an idle line of the second order and means for effecting the connections, .ofa shifting device adapted to divide lines Whose condition has become modified into groups of which one group. comprises such of the modified lines as have been switched into readi' ness for connection, whilst another group comprises lines which have become modied whilst the connecting means is connecting lines ofthe first group.

3. Arrangement according to claim 2 in which there are means for disabling from connection lines of the second group and means whereby the lines of the second group are simultaneously enabled as soon as all thellines of the firstgroup have been dealt wit 1.

- 4. Arrangement according to claim 2 in which the shifting device` is normally in-v operative and in which there are means operative upol. all the 'lines of the second order becoming engaged for bringing the shifting .device into operation and means whereby l ell lines of the second group' are smulwhich'engaes the lines of the second order taneonsl enabled for connection as soon as -and part y devices actuated when lines 10 anyof the lines of the second orderb'ccomes of the rst order become modified. free` after'the lines of the first group'have In testimony that I claim the foregoing 5 4been dealt with. y f v as my invention I have signed my name this 5. Arr ement according to claimv2 in 22nd day of July, 1921. which thnsiifting device consists of a 'rely f adapted to be controlled partly by Ja device" GTTHIU"` NSGRIUS TUI-NDER- 

